What are some of the common arguments for and against trade restrictions?

Choose a position and describe why you think it is valid.

http://www.google.com/search?q=trade+restrictions+pro+con&rls=com.microsoft:en-us:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA

Let us know what YOU THINK, and someone here will be happy to comment on your ideas.